One of the largest traces of the Rury history comes from the descendants of Reginald, Lord of the Isles, from whom are descended the clans MacDonald and MacRurie.

Book: Clans, Septs & Regements of The Scottish Highlands

Although the MacRuairi lands passed into the hands of the McDonald clan, the MacRuairi (McRury) name is still represented by a considerable number of clansman in the land of our sires. They call themselves the McRurys. McRury is therefore the oldest Clan name in Uist, as a sept, they haven't retrieved their fallen fortunes of their house, but they have at least succeeded in preserving the name from being lost, and they have done nothing to tarnish that name, or the fair fame of MacRuairi of Garmoran and the North Isles.
This is My Family Name Surch Mary

King Malcolm IV who died 1165 crushed a rebellion in Moray, defeating the army of the Lord of the Isles at Renfrew in 1164, and bringing Gallowag under control of the crown. The Lord of the Isles, whose forces he defeated at Renfrew was Somerled, the progenitor of the greatest of clans, the Clan Donald, and also the clans McDougall and MacRury.

The descent of this clan (Ranald) is from John, Lord of the Isles, who married Ami, daughter and heiress of Ruarai' (Rory or Roderic) of the Isles, a collateral branch of the Mac Donalds, about 1337. From Raonal, the issue of this marriage, arose the generic appellation, Clan Ranald, and from Aluinn (beautiful), his son, is derived the patronymic of the chief, Mac Mhic Allan.
>From the time of Ruarai', who was chief in the early part of the fifteenth century, the clan became distinguished in the transactions of the country, and arose in importance, as the elder branch, from a series of reverses, consequent on their collisions with government, were depressed, until at last they were so reduced, that Clan Ranald, as the nearest branch, was, by a modification of the Tanis law, acknowledged chief about 1530; and the abilities of his successors enabled them long to contend for possion of the dignity, when the others had acquired means to resume their former position. The hereditary honour of Captain of Clan Ranald could never be disputed, which not only referred to his own dependants, but denoted his rank among all who claimed descent from Ranald of the Isles.

The Galley Conjectural Tree, 7th Century to 15th Century

Somerled - Local King of Argyle, King of the South Isles from 1156 was killed in 1164.
Ronald (son of Somerled)- King of the South Isles died 1207.
Ruari or Alan (son of Ronald) - The Lord of Garmoran & the North Isles, Lord of Vist & Barra died 1284.
Amie (daughter of Ruari) - Heiress of the MacRuaris. Married John - Lord of the Isles. He divorced her and her land went to him in 1372 (McDonald Clan)
Ronald (son of Amie and John) - received his mothers lands by charter confirmed by Robert II, 1373. He was Lord of Garmoran died 1386.
Allan (son of Ronald) Laird of Moidart died c. 1429 (His brother Donald's Clan becomes the McDonalds of Glengarry).
Ruari (son of Allan) - Captain of Clan Ronald. Now the McDonalds of Clan Ronold.

Septs under McDonald Clan

McRorie
McRurie
Rorie
Ryrie
Rury

Other Rury's from Scotland extracted from various documents, but not directly connected:

Make Rori, Thomas, father
Make Rori, Ninian, son, died 1298 in Carlisle prison
Make Rori, Brice, father
Make Rori, Gilepatrike, son, died 1298 in Carlisle prison
Makrore Mc Kilfersen, Alexander, tenant of Kilkewane, Kintyre circa 1500
McRorie, Gillechallome in Abironethie, circa 1600
M'Rorie, Donald Dew in Ballince, denounced as rebels in 1675
M'Rorie, John in Ballince, denounced as rebels in 1675
M'Rourie, John in Ardtounsichever, denounced as rebels in 1675
M'Rory, Taskel of Inverness, Jacobite prisoner

The Surnames of Scotland by George F. Black, PH.D., 1946, Page: 562-563 include
MACRORY, Macrorie, Macrury. G. MacRuairidh, 'son of Ruadhri.' See Rory. John filius Rothri was present at pleas held at Dall in Atholl, 1264 (RPSA., p. 349). Rouland fiz Aleyn Mac Rotherik of the counte of Innernys rendered homage, 1296 (Bain, II, p.210). Report was made in 1297 of lawless proceedings on the part of Lochlan and Rodric Macrogri (of Garmoran) in the West Highlands in ravaging Skye and Lewis and burning ships of Edward I of England commanded by Alexander of Islay, Edward's admiral in the isles (Bain, II, 903). Ninian, son of Thomas Make Rori, and Gillepatrike, son of Brice Make Rori, Galwegian hostages, died in Carlisle prison, 1298 (ibid., p. 301; Hist. Docs. II, p. 426). Alexander Makrore Mc Kilfersen was tenant of Kilkewane, Kintyre, 1500 (E.,R., XII, p. 707). Gillechallome McRorie in Abironethie was fined for resetting Clan Gregor 1613 (RPC., XIV, p. 629). Donald Dew M'Rorie and John M'Rorie in Ballince, and John M'Rourie in Ardtounsichever were denounced r!
ebels in 1675 (HP., I) and Taskel M'Rory of Inverness was a Jacobite prisoner of the '45 (Prisoners, III, p. 184). Macrury is said today to be the oldest clan name in Uist. MacRuaraidh and MacIlliruaidh, Islay surnames, are sometimes Anglicized Reid (Celt, Mon., X), and Mackury is a Barra form of the name. Makreury 1427, McKrory 1682, McRorie 1675, Mc royre c.1520, Mc royri 1522.